I. Field of the Invention
The invention relates to the drive assemblies of vehicles comprising an internal combustion engine, and control methods for such assemblies.
II. Description of Related Art
FIG. 1 represents one conventional exemplary embodiment of such an assembly. The assembly 2 forms a motor vehicle drive assembly. In a manner known per se, this assembly comprises an internal combustion engine 4, such as a petrol motor or a diesel motor. It comprises an alternator-starter formed by a variable reluctance machine 6 of a type known per se. This machine 6 is mechanically linked to the engine 4 to provide the latter with a torque, particularly in order to start it when it is stopped. This mechanical link of a type known per se carries the reference 8 in FIG. 1. The assembly comprises a control unit 10 comprising conventional computer means enabling it to control the various units of the assembly as will be seen below. The assembly 2 also comprises an inverter 12 by means of which the control unit 10 drives the operation of the machine 6.
The assembly 2 also comprises a position sensor and/or a speed sensor 14 enabling the unit 10 to know a measurement of the speed of the machine 6 at each instant.
FIG. 2 represents a conventional inverter topology for controlling the motor phase. In this FIG. 2, VDC represents the DC voltage powering the inverter, I1 and I2 two electric switches that can be switched open and closed and D1 and D2 are two diodes.
A control method for such a drive assembly installed on a vehicle (comprising, as has been seen, a reluctance machine associated with an inverter) is normally used to control the torque delivered by this drive assembly.